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perfect symmetry... whats this?

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Nate

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May 17, 2003
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Whats the jagged circle that can be seen between each arrow in the center of the stone? It is on every H&A. What facets cause this affect? Can it be gotten rid of?

Just curious.
 

rbjd

Shiny_Rock
Joined
Feb 4, 2003
Messages
154
Not sure what you are referring to Nate. Are you talking about the table reflection (looks like a miniature version of the table in the center)?
 

Mara

Super_Ideal_Rock
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Oct 30, 2002
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31,003
Check out Rhino's site..he talks about the scintillation that occurs around the table area--I believe it's the area you are talking about. Not sure what CAUSES it persay, but I *think* it's supposed to be a good thing for the 'dark flashes' of scint in well cut stones to balance out the 'sparkle' (in late Friday afternoon post-lunch coma terms).
 

mike04456

Brilliant_Rock
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Nov 20, 2002
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1,441
That, if I'm understanding you correctly, is the table reflection, and to make it go away, you have to make the stone so shallow that you start getting a girdle reflection and basically kill the brilliance. You don't want it to go away.

There's no such thing as a perfect diamond. There are trade-offs in every decision the cutter makes.
 

Nate

Shiny_Rock
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Nah, I can see the table reflection. This has jagged edges. Look at my second post in this thread.
 

rbjd

Shiny_Rock
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Feb 4, 2003
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154
Mara's right. Anything that shows up black in a firescope image is something that is going to reflect light back. You WANT those little arrows pointing toward the center to be there.

The little arrows or triangle you are referring to are related to the star facets. Look at the star facets and compare the two.
 

Garry H (Cut Nut)

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Nate can you see this effect with your naked eye?

(Is your head the same shape and color as a camera lens?)

Mara and RBJD black in an ideal-scope is not going to show light return (contrary to Rhino's education program and mistaken belief).

This black is the lack of illuination caused by the ever present observers head.
 

Mara

Super_Ideal_Rock
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31,003

----------------
On 7/11/2003 6:38:49 PM Cut Nut wrote:

Mara and RBJD black in an ideal-scope is not going to show light return (contrary to Rhino's education program and mistaken belief).

This black is the lack of illuination caused by the ever present observers head.

----------------

Would it be scintillation? I thought black meant scint spots? Or is it ALWAYS going to be the head? Even in an excellently cut stone?

 

rbjd

Shiny_Rock
Joined
Feb 4, 2003
Messages
154
I fail to see how the shadow of a head could cause the black areas in a FIRESCOPE image.

As for the IdealScope (which I did not originally mention), if used according to the instructions (like in the picture Garry has on his website of him using the IdealScope) your head is clearly NOT getting in the way of the light for the IdealScope so how could it cause the black areas?

Also, the ARROWS are black. Of course they reflect light. Take a look at any of the BrillianceScope readings on GoodOldGold's website for H&A diamonds. Take a look at a real H&A in person. Are you seriously going to tell me the arrows don't reflect light? It is quite obvious that the areas which read black on the FIRESCOPE images throw back intense amounts of light.

The little triangles Nate is inquiring about are reflections of the black areas in the star facets as seen in a Firescope. Those areas reflect light intensely in a well cut stone.
 

Hest88

Ideal_Rock
Joined
Jan 22, 2003
Messages
4,357
Just a quick comment:

Nate, if we posit that the jaggedness is an instrinsic part of a H&A stone, and we accept that a H&A means it's an ideal-cut stone, then why would we want to get rid of it? Shouldn't we accept it as something that must contribute to the beauty of the stone? That would be like someone smuggling a fine raw-milk French triple-cream cheese over, and having the recipient wrinkle his nose at the smell and say, "Can't we get rid of that strong smell? The brie I buy at the supermarket doesn't have that smell!"
 

Garry H (Cut Nut)

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The design of the FS IS LS etc is such that the lens area causes darkness in a diamond the exact same way a lens on a camera or a humans head does.

When you look at a H&A's diamond in soft lighting like a cloudy day you can see the same black star.

Black = no light.
Black provides contrast that makes adjacent brighter areas appear more brilliant - we call this scintillation as the black - white flashing occurs when the diamond is moved.

But black in a face on view is not scintillation and it is definetely not brightness.

When you look at a diamond there are 1 possible cause of darkness - you are seeing a light source that is very dim or non existant.
2 types are 1. light that has come from behind the diamond = leakage = white or pale in Ideal-scope etc
2. darkness from the environment above the girdle. In this case the only source of darkness is the lens.

The IS has an effective 6inch head at 14 inches viewing distance.
The Firescope has the same but very close up (about 10 inches).

Jonathon has never told anyone the proportions of his device.

Does that make my earlier post comprehensable?
 

rbjd

Shiny_Rock
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Feb 4, 2003
Messages
154
In the head-on view the black areas such as the arrows seen in a FS (firescope), IS (idealscope), or LS (lightscope) image is the darkness of the lens. Is that a reflection? What do you call that? It is obviously not leakage.

It seems that if light is shining directly onto these areas (such as in the case of the BrillanceScope design) they will return very bright light. The areas that Nate has highlighted are just that: areas which will return very bright light (like a mirror) when it shines on them. Either way, it seems like they are quite good.

Actually, buried in Eightstar's marketing hype on their website I think they refer to these features (the ones Nate has circled in red) as a form of the "heart" pattern seen in the table. They call it the "heart motif". (Although to my eye they look more like arrows pointed at the culet. Actually, they look like mouse cursors! Actually, they also look like M.C. Escher's planarians.) See Eightstar's diagram entitled "Perfect and distinct star pattern." I won't post it here because I don't want Richard von Ego to sue me.

Whatever you call this feature, it is clearly symmetrical (in a perfectly cut diamond) and says quite a lot about the symmetry of a well cut diamond. It is just another fascinating pattern to be found in a perfectly symmetrical H&A diamond. There are many. Keep looking.

This feature is not limited to Eightstar, but is a component of all finely cut H&A diamonds such as those Jonathan sells and those sold by SuperbCert. In fact the picture Nate posted looks like a SuperbCert shot. Correct me if I'm wrong.
 

Rhino

Ideal_Rock
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Gary we've had this discussion before and the very software you promote (DiamCalc) which I also use proves you wrong. In a discussion we had on diamondtalk sometime in the past I asked Serg POINT BLANK after observing a .gem file we generated ... "ON WHAT FACETS ARE WE OBSERVING THE MOST INTENSE FIRE? ANSWER: THE PAVILION MAINS." You can go to any .gem file on our website, play that file (like in Disco light
) and you will see in virtual reality the brightest flashes of color coming off the facets that appear "black" in the LightScope... the pavilion mains. In Peter Yantzers recent article on the MSU site he referred to these parts of the diamond that reflect back light to the observer at the "high angles". Also if you do a ray trace on an H&A diamond and observe the path of light within and without the stone the STRONGEST reflections are those which emanate off the pavilion mains. Just like the BrillianceScope shows very plainly in it's graphics.

DiamCalc, GemAdvisor, the digital BrillianceScope, the analogue BrillianceScope, Yantzer, EightStar and every other resource I can think of all disagree with your interpretation of the blacks under the red reflectors in real world light conditions and optical devices like the b'scope.

To quote the latest research word for word as posted on the MSU site...

An elegant way to test a gem is the Firescope, invented in Japan in 1984.17 The Firescope is a simple device that uses a small cap, painted red on the inside, a diffused white-light source and a 10X eyepiece . The Firescope does not measure fire but instead shows the gem’s ability, per crown zone, to bring light to an observer’s eye . Under a Firescope, light leakage through the pavilion appears white and high angles appear black.

There it is as plain as the nose on our faces.

I still love you though Gary.


Peace,
Rhino
 

rbjd

Shiny_Rock
Joined
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Messages
154
There you go Nate, Rhino has your answer. The black areas are the pavilion mains (or their reflections). They are an integral part of the reason H&A's sparkle like they do.

Professor Rhino, a question: Are ALL the black areas in the Firescope image reflections of the Pavilion mains or are there other facets causing this?
 

Rhino

Ideal_Rock
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Just another note.

The more light reflected in the "high angles" (ie IN YOUR FACE) THE MORE INTENSE THE LIGHT RETURN and the more scintillating it will be!!! However ... too much black is no good either. There must be a nice balance between light being reflected at the high angles and the medium angles.

Gary is using a term of "scintillation" that breaks from traditional definition and noone (in the industry that I know of) defines it the way Gary is doing here. Gary is referring to something which he refers to as "static scintillation" which has more to do with "contrast brilliance" than it does scintillation.
The proper and more traditional definition of scintillation is "The movement of white and colored light within the diamond as the
a. diamond is moving
b. the observer is moving
c. the light source is moving
d. all of the above (I'm getting dizzy!)

Static scintillation is an oxymoron. Observing scintillation within a diamond involves movement. Static by definition means standing still. COMPLETELY STILL AND ONLY in the face up position. Therefore the term "static scintillation" makes no sense to me. CONTRAST BRILLIANCE on the other hand makes alot of sense and this is what I think my dear friend may be confusing.

Peace,
Rhino
 

Rhino

Ideal_Rock
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Good question rbjd,

All the blacks you observe under LightScope/FireScope/IdealScope are not caused by the pavilion mains. While the pavilion mains are primary sources for light being reflected at the high angles my research has shown me that the minor facets (particularly the lower girdles and the stars) affect the presence of even more light that can be reflected at the high angles.

When the lower girdles are cut to a particular lengh it causes the presence of blacks between the arrow shafts (as seen in the LightScope graphic Nate posted above and more pronounced blacks which can be seen through the star facets. If the star facets are more "closed" (ie. cut to a shorter %) this closes the windows on more light that could be reflected at the high angles. OPEN THOSE WINDOWS and you allow MORE light to reflect at the higher angles thus producing different optical results.

This really gets down to the nitty gritty of differentiating between the super ideals and some have a preference for one type over another. I have my personal preferences but compared to the crap that's being offered out there today they're all beautiful.


So in short stars and lower girdles (more particularly the lower girdles) play a major role in the optics of the diamond. In GIA's article on the subject of DCLR (dispersed colored light return) they reported that diamonds of the longer star (more open windows) and longer lower girdle combos (longer lower girdles produce more light at the high angles) produced the higher DCLR (based on a model they used back in their initial study of brilliance back in 199
.

Peace,
Rhino
 

Rhino

Ideal_Rock
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----------------
On 7/11/2003 11:26:49 PM Cut Nut wrote:
The design of the FS IS LS etc is such that the lens area causes darkness in a diamond the exact same way a lens on a camera or a humans head does.

When you look at a H&A's diamond in soft lighting like a cloudy day you can see the same black star.

Black = no light.
Black provides contrast that makes adjacent brighter areas appear more brilliant - we call this scintillation as the black - white flashing occurs when the diamond is moved.

But black in a face on view is not scintillation and it is definetely not brightness.

When you look at a diamond there are 1 possible cause of darkness - you are seeing a light source that is very dim or non existant.
2 types are 1. light that has come from behind the diamond = leakage = white or pale in Ideal-scope etc
2. darkness from the environment above the girdle. In this case the only source of darkness is the lens.

The IS has an effective 6inch head at 14 inches viewing distance.
The Firescope has the same but very close up (about 10 inches).

Jonathon has never told anyone the proportions of his device.

Does that make my earlier post comprehensable? ----------------
Gary I do not disagree with this. You are correct with regards to these comments. In diffuse light conditions when you point the diamond at your face you'll see head on reflection (unless a light bulb is attached to your nose). Diffuse light complements contrast brilliance which is awesome in precision cut stones.

I think the miscommunication here is that Gary is saying that when you are OBSERVING BLACK WE ARE NOT OBSERVING LIGHT. I would add to this ... take that diamond into real every day light conditions and you'll see some extreme fire coming off of those facets that were being blocked in the scopes by our heads. Or ... if we're observing an H&A diamond in an overcast day you'll be able to observe the most beautiful contrast brilliance possible within a round brilliant cut (this is little to do with intensity of light return as the sun is hidden behind a cloud.) However ... let that sun come out from behind the cloud and it strikes throug the crown and onto a pavilion main (arrow facet) and you're going to burn a retina!


Are we on the same page mate?

Peace,
Rhino
 

Rhino

Ideal_Rock
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----------------
On 7/12/2003 1:24:57 AM Cut Nut wrote:

All very nice, but my original point was you can not see this stuff - features, not benefits!!

RvE he he he----------------
Hehe... depends on how old you may be and whether you have your glasses on or not. I have people who DO come in here and see these differences though Gary and make the seperations with their own 2 eyes. I love em all though and purchase all flavors. Admittedly some I'll take on memo and scan in as examples too.
I've built quite a database.
Nite nite.
Rhino
 
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